Implantable surgical devices such as surgical fasteners, clips, staples, partitions, stents, and sutures are typically employed in surgical procedures to hold body tissue together, to separate body tissue, and/or to promote the healing and joining of the tissue. Such surgical devices are often made from synthetic non-biodegradable and biodegradable or bioerodible polymers. Synthetic absorbable multifilament sutures such as Dexon, Vicryl, and Polysorb, commercially available from Davis & Geck (Danbury, Conn.), Ethicon, Inc. (Somerville, N.J.), and United States Surgical Corporation (Norwalk, Conn.), respectively, are well known in the industry. An advantage of non-biodegradable implants is that they generally retain their structural integrity and properties while remaining within the body. An advantage of biodegradable devices is that, once implanted, they often do not need to be removed by a separate surgical operation since they may be degraded and absorbed by the body. For example, U.S. Pat. No. 5,889,075 describes a surgical suture fabricated from a copolymer containing dioxanone, trimethylene carbonate and glycolide that is treated with gamma radiation to enhance bioabsorbability without adversely effecting handling properties.
However, non-biodegradable polymeric implants are often temporary and require removal from the body, which can traumatize the patient. While biodegradable polymers are often employed when temporary implants are needed, these devices often degrade too quickly, so that polymer structure and function is prematurely lost, or too slowly, so that prolonged polymer/implant presence interferes with normal body function. Hence, a polymer whose structure and/or function can be degraded at a selected time would be useful in surgical implants.